This excerpt taken from the GGP DEF 14A filed Apr 12, 2006.
Procedure for Exercise; Rights as a Stockholder. Any Option granted hereunder shall be exercisable according to the terms of the Plan and at such times and under such conditions as determined by the Committee and set forth in the Award Agreement. If the Committee provides that any Stock Option is exercisable only in installments, the Committee may at any time waive such installment exercise provisions, in whole or in part, based on such factors as the Committee may determine. The Committee may at any time, in whole or in part, accelerate the exercisability of any Stock Option.
An Option shall be deemed exercised when the Company receives: (i) written notice of exercise (in accordance with the Award Agreement) from the person entitled to exercise the Option, and (ii) full payment for the Shares with respect to which the Option is exercised. Full payment may consist of any consideration and method of payment authorized by the Committee and permitted by the Award Agreement and by the Plan as described under Section 7(c) above. Shares issued upon exercise of an Option shall be issued in the name of the Recipient. Until the Shares are issued (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of the Company), no right to vote or receive dividends or any other rights as a stockholder shall exist with respect to the optioned Stock, notwithstanding the exercise of the Option. The Company shall issue (or cause to be issued) such Shares promptly after the Option is exercised. No adjustment will be made for a dividend or other right for which the record date is prior to the date the Shares are issued, except as provided in Section 13 of the Plan.(1)
Exercising an Option in any manner shall decrease the number of Shares thereafter available, both for purposes of the Plan and for sale under the Option, by the number of Shares as to which the Option is exercised.